Answer:
160 degrees
Step-by-step explanation:
Step 1: A straight line is 180 degrees. So 180 - 100, is 80 degrees. as the opposite angle measurement of the 100 degree.
Step 2: An isosceles triangle has two equal angle measurements, so two of its angles are 80 degrees.
Step 3: All angles in a triangle equal 180 degrees. So add them up (we will call the missing angle, Z) 180 = 80+80+Z. which equals 180= 160+z
Step 4: Solve it. You subtract 160 from both side which comes out to 20 = Z.
Step 5: Now you have the opposite angle of X. Going back to step 1, A straight angle is 180 degrees. 180 - 20 = 160. X = 160 degrees
